Does wearing a face mask help prevent the spread of COVID-19? Yes, and here is an article reviewing the scientific research on the matter. This article is dry and boring, but presents the science if you want to see it.
Here is an article showing that even if a mask doesn't completely prevent exposure to the virus altogether, it reduces the viral load of the exposure, consequently reducing the severity of the disease and ultimately providing the "immunity" of recovering from it. Note: if you read nothing else here, please read the following article.
Finally, an article that contains irrefutable points that help you decide for yourself about the efficacy of wearing masks. You don't need experts or politicians or media talking heads to tell you what is sensible--decide for yourself.
You might have your own reasons for not wearing one. I wish you would, but I get it. Please, though, don't say that research hasn't proven masks to have an effect or that our own reason doesn't direct us to wear one.